Projects
Inorganic Photocharging Battery (Inorganic SolStore) – Theoretical Study by First Principle Simulation
Project description
The concept of the integrated photocharging battery combines a solar cell with one electrode of a Li-ion battery to minimize weight and size. A promising approach involves incorporating halide perovskites as photovoltaic absorbers and Li-ion battery electrodes in commercial applications. Halide perovskites, unlike the covalent or polar semiconductor compounds that are typically used in PV devices, possess mixed ionic-covalent bonding character. This property enables halide perovskites to serve as multifunctional materials for both, light-harvesting and Li storage. To this end, my project involves the interpretation of the interaction between the Li element and the halide perovskite crystals and we aim to theoretically assess the feasibility of such integrated device.
Project outcomes
In this project, we studied the energetic and electronic aspects of Li-perovskite materials system through first-principle calculations. Using LixCsPbI3 as a model system, we systematically investigated the behavior of interstitial Li atoms and their impact on the electronic structure of the halide perovskite crystal. The migration barriers for Li ions in the perovskite material are comparable to those in commercialized electrode materials in Li-ion batteries. However, the theoretical uptake limit of Li in the material is limited to a small content. Furthermore, the interstitial Li significantly increases the band gap of the perovskite material, resulting in poor sunlight absorption.
Although ABX3 halide perovskites have been shown to be unsuitable for photocharging batteries, the theoretical approach discussed in this project can serve as a comprehensive workflow applicable to other material systems to search for more suitable photo-battery materials.
Supervisor and Dissertation
Prof. Dr. Christian Elsässer
Wei Wei completed his dissertation in November 2023.
Dissertation: Theoretical atomic-scale modelling of perovskite-type photo-battery materials
Current position
Research associate at the Fraunhofer ENAS in Chemnitz. The Fraunhofer ENAS operates in the field of smart systems integration by using micro and nano technologies.